Clinical course of patients with chronic limb-threatening ischemia developing COVID-19

Background: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2, has overwhelmed healthcare systems. Patients with lower extremity artery disease are at high risk of cardiovascular events, of whom chronic limb-threatening ischemia (CLTI) is the most severe manifestation of peripheral artery disease with an increased risk of mortality compared to patients with intermittent claudication. However, the clinical course of CLTI patients with COVID-19 has not been reported.

Methods: We retrospectively surveyed clinical course for 25 CLTI patients who developed COVID-19 during the "sixth wave" of the pandemic in Japan, which started in January 2022. The primary outcome measure was the 30-day mortality after the diagnosis of COVID-19. We also compared the mortality risk of the 18 COVID-19 patients who underwent initial endovascular treatment with that of 1867 CLTI patients who received initial endovascular treatment before December 2019 (i.e. before the COVID-19 pandemic) (control group). Cox proportional hazard regression model was used to evaluate the effect of COVID-19 on the mortality. To confirm the robustness of these results, we added the analysis with inverse probability weighting (IPW) based on the propensity score for the COVID-19.

Results: The 30-day mortality after the diagnosis of COVID-19 reached 20 %; the 95 % confidence interval (CI) of the proportion was calculated to be 7 % to 41 % by the Clopper-Pearson exact method. Cox regression analysis demonstrated the mortality risk was significantly higher in patients developing COVID-19 than in control group [adjusted hazard ratio, 3.08 (95 % CI, 1.13-8.37); p = 0.027]. The IPW analysis also confirmed the significant association of COVID-19 with the mortality risk [hazard ratio, 3.97 (95 % CI 1.54-10.21, p = 0.004)].

Conclusion: In CLTI patients, the 30-day mortality after the diagnosis of COVID-19 reached 20 % (95 % CI, 7 % to 41 %) under the pandemic in January 2022, and patients developing COVID-19 had a significantly higher mortality risk than those treated before the pandemic.